Field
Exemplary Embodiments of the present disclosure relate to an etching method, in particular, to a method of simultaneously etching a first region and a second region, the first region including a multi-layer film configured by alternately stacking silicon oxide films and silicon nitride films, and the second region including a silicon oxide film having a film thickness thicker than the film thickness of the silicon oxide films in the first region.
Related Background Art
As one type of a semiconductor device, a NAND type flash memory device having a three-dimensional structure is known. In manufacture of the NAND type flash memory device having a three-dimensional structure, etching of a multi-layer film configured by alternately stacking silicon oxide films and silicon nitride films is performed to form a deep hole in the multi-layer film. Such etching is described in U.S. Patent Application Publication No. 2013/0059450.
Specifically, in U.S. Patent Application Publication 2013/0059450, a method of etching the multi-layer film by exposing a workpiece which includes a mask on the multi-layer film to plasma of a processing gas is described.